1. Islamic University of Gaza
Organic chemistry A
Chapter 3
Alkanes
By Prof. Dr.
Adel M. Awadallah
Islamic University of Gaza

2. Alkanes and Cycloalkanes
Hydrocarbons (contain only carbon and hydrogen)
Saturated: (Contain only single bonds)
Alkanes (CnH2N + 2 )
Cycloalkanes (CnH2N )
b) Unsaturated: contain
Alkenes: double bonds (,,,CnH2N)
Alkynes: triple bonds ((CnH2N - 2)
Aromatic: benzene like compounds

3. The structure of alkanes

4. Alkyl groups

5. Nomenclature of substituted alkanes
Choose the largest continuous chain
Start numbering (lowest possible numbering)
List substituents alphabitically.
Use di, tri, tetra, penta, hexa, hepta, octa, nona, deca for identical groups
Examples

6. If there are two equally long continuous chains, choose the one with most branches

7. Conformations of Alkanes:
Conformers: Stereoisomers that are interconvertible by bond rotation

8. Potential Energy Changes in Ethane

9. Propane and Butane

10. Conformations of n-butane

12. Pentane and Hexane

13. Classes of carbon atoms and hydrogen atoms

14. Physical properties of alkanes
1) Water insoluble
2) low boiling point, which increases upon increasing the number of carbons in the alkane
3) branched alkanes have lower boiling points than the corresponding long chain alkanes

16. Industrial Sources

17. Preparation of Alkanes

18. Examples

24. Orientation of Halogenation

28. Ease of Abstraction of Hydrogen atoms

31. Transition State for Halogenation
Factors that tend to stabilize the free radical tend to stabilize the incipient free radical in the transition state

32. Non-rearrangement of free radical